The present invention relates to a water softener, particularly adapted to be installed upstream the home distribution network.
It is well known that the percentage of calcium in the water supplied by the public distribution network, is variable from one place to another and sometimes with time, but such a percentage is generally higher than the optimal quantity required by the human body.
It also known that an excessive quantity of calcium like an excessive deficiency, may cause troubles for the health of the users, but also for the hydraulic devices through which calcium rich water is flowing. More particularly an excessive quantity of calcium dissolved in water causes deposit of lime layers inside the pipes and in the long run said scaling cause pipe clogging and decrease of performances of said devices, sometimes requiring replacement of the corresponding element or the entire device.
In order to remove these drawbacks water undergoes a softening treatment generally consisting in filtering water with special softening substances such as ionic resins blocking the calcium ion.
More particularly said ion exchanging resins convert calcium and magnesium salts, tending to be deposited with water heating, into sodium salts that on the contrary remain in solution.
Indeed, when the cationic resins are strong in sodium cycle, this free base is sodium saturated; said resins by natural affinity, when crossed by hard water, capture the calcium ion and release the sodium ion generating said exchange phenomenon that can be considered as instantaneous.
In such a process the resins release sodium up to its exhaustion, gradually losing their filtering feature. In this situation the resins must undergo a regeneration treatment by which they are supplied again with sodium, substantially undergoing the opposite process now described.
According to the prior art, regeneration generally consists firstly in dissolving the captured calcium through a solution generally comprising sodium chloride dissolved in water, and then removing calcium washing the regenerated resin.
In order to carry out such a treatment special softeners are used, installed upstream the distribution circuit of water to be treated and allow to control the level of water hardness.
The known softeners generally comprise a vessel containing the ionic resin associated with a distributor comprising a manifold body in which there is an inlet pipe for water to be treated and an outlet pipe for treated water.
Inside the manifold body there is a plurality of inner ducts that can be intercepted through flow ways belonging to a spool sliding inside said manifold body and moved by an actuator unit.
More particularly the actuator unit moves the spool to define different mutual positions between the flow ways and the inner ducts, each position being adapted to define different water paths.
The different spool positions therefore define the different operative stages of the device, comprising as above stated, a working or processing stage in which water is being filtered and delivered to the outlet duct, a regeneration stage of the ionic resin and a washing stage of said resin.